Study of CO Radicals on Magnesium Oxide with Electron Paramagnetic Resonance Techniques

Abstract

It has been determined that a fraction of the carbon monoxide which is adsorbed on magnesium oxide is in a paramagnetic state. Magnesium oxide was degassed at 850°C and 10−5 Torr for 16 h, cooled to room temperature, and then exposed to 150 Torr of high‐purity carbon monoxide. The resulting paramagneticspectrum grew slowly for several weeks. This paper describes the spectrum of the adsorbed CO radical (g∥=2.0021, g∂=2.0055, ax =27 G, ay =11 G, az =0 G), the probable type of site on which the molecule is adsorbed, its bonding, and the effect of evacuating at elevated temperatures.